Problem Receiving MMS
 

I recently flashed a stock VZW rom back on my phone, and everything seems to be working fine. I can send normal text messages and call and whatnot, but the other day someone sent me a picture message and I wasn't able to get it. I saw the notification saying that it was trying to connect data network by dialing #777, but it says that my username and password are wrong. What username and password? I checked the settings for that connection, and I saw where there was a two blank boxes for the username/password options, but I didn't know what to put. Any help on getting this working?